-// typedef std::vector<exvector> exvectorvector;
-typedef std::vector<exvector,malloc_alloc> exvectorvector; // CINT does not like vector<...,default_alloc>
-
-/** Base class for color object */
+// Cint doesn't like vector<..,default_alloc> but malloc_alloc is
+// unstandardized and not supported by newer GCCs.
+#if defined(__GNUC__) && ((__GNUC__ == 2) && (__GNUC_MINOR__ < 97))
+typedef std::vector<exvector,malloc_alloc> exvectorvector;
+#else
+typedef std::vector<exvector> exvectorvector;
+#endif
+
+
+/** This class holds an object carrying color indices (of class coloridx).
+ * It can represent the generators T_a and structure constants f_abc/d_abc
+ * of SU(3), the unity element ONE of the Lie algebra of SU(3), or the
+ * unity matrix delta8. Together, these objects are used to implement the
+ * Lie algebra su(3), as required for calculations in quantum
+ * chromodynamics. A representation label (an unsigned integer) is used to
+ * distinguish elements from different Lie algebras (only objects with the
+ * same representation label "interact" with each other). */